1. Field of the Invention
This invention relates generally to a fin-and-tube type heat exchanger. More particularly, the present invention relates to a fin-and-tube type heat exchanger having a worked fin surface which is suitably used for cross-fin type heat exchangers such as room air conditioners, package air conditioners, and for louver corrugate type heat exchangers such as can radiators, condensors, evaporators, and so forth.
2. Description of the Prior Art
An example of a fin-and-tube type heat exchanger is disclosed in U.S. Pat. Specification No. 3,438,433. The heat exchanger of this reference involves the problem that the temperature boundary layer of the upstream louver in the air flow overlaps the downstream louver, thereby reducing the heat transfer rate of the downstream louver.
Various attempts have been made to obviate this problem, and U.S. Pat. Specification No. 3,380,518 illustrates one of such attempts. In this prior art apparatus, the louvers are cut alternately on both sides of the fins and their height is changed so that the temperature boundary layer of the upstream louver does not adversely affect the downstream louver. However, the prior art involves another problem in that the gap between adjacent louvers is too small for the air to smoothly flow therethrough, so that the heat transfer rate is further reduced.
Furthermore, if the louvers are inclined with respect the air flow, or if an attack angle is provided, resistance of the air flow increases, thereby increasing pressure loss.